Anyone have any tips on making an amp-hour meter for a solar power setup?

I have about 20 amps of charging current going into a bank of 440Ah, 12V
batteries feeding a 500W inverter.

I have a 200A 50mV shunt that will be used inline with the battery.

I'm going to take the voltage from the shunt to feed a voltage to frequency
IC, and then count the pulses.  There will be two V to F circuits, one for
charge, the other for discharge.  The pulses will feed into a '54 driving a
16x2 line LCD display.

Anyone see anything wrong with the above plan?
Thanks in advance
Dave